Aculvert to pass a 25-year peak runoff rate of 0.2 m3/s under a roadway. The headwater depthis 1.70 m; the inlet and the outlet channels are both trapezoidal with bottom widths of 2 m, side slope of 2:1 (H:V), lined with riprap, and have a longitudinal slopeof 0.1%. Local drainage regulations require a minimum culvert diameter of 455 mm. (a) What is the minimum required diameter for a Type 2 flow

Air is to be cooled in the evaporator section of a refrigerator by passing it over a bank of 0.8-cm-outer-diameter and 0.4-m-long tubes inside which the refrigerant is evaporating at -20°c. air approaches the tube bank in the normal direction at 0°c and 1 atm with a mean velocity of 4 m/s. the tubes are arranged in-line with longitudinal and transverse pitches of sl- st 1.5 cm. there are 30 rows in the flow direction with 15 tubes in each row. determine (a) the refrigeration capacity of this system and (b) pressure drop across the tube bank. evaluate the air properties at an assumed mean temperature of -5°c and 1 atm. is this a good assumption?